Controlling system for automatic switching apparatus.



A. M. BULLARD & J. N. REYNOLDS. M. R. BULLARD, ADIIHISTBATRIX 01' A. M. BULLABD, DEG'D.

CONTROLLING SYSTEM FOR AUTOMATIC SWITCHING APPARATUS. APYLIUATION rum) APR. 1, 1910.

1,020, 1 85. Patented Mar. 12, 1912. 5 sHgETs-s Egg- 1.

Fig.

S $3 //7ve/7f0rs:

. A. M. BULLARD & J. N. REYNOLDS.

1L2. BULLAED, ADMINISTRATEIX or A. m. BULLARD, nno'n. CONTROLLING SYSTEM FOR AUTOMATIC SWITCHING APPARATUS.

- APPLICATION FILED AFB.1,1910.

1 1,020,135, Patented Mar.12, 1912'.

5 SHEETS-SHEET 2.,

A. M. BULLARD & J. N.-RBYNOLDS.

M. n. BULLAE-D ADMINISTRATRIX or A. m. BULLAED, DEGD. CONTROLLING SYSTEM FOR AUTOMATIC SWITCHING APPARATUS. APPLICATION FILED APR.1,1910.

1,020, 1 85. Patented Mar. 12, 1912.

5 SHEETS-SHEET 4 R A. M. BULLARD & J. N. REYNOLDS. M. R. BULLARD, ADMINISTRATRIX or A. MNBULLABD, DEG'D. CONTROLLING SYSTEM FOR AUTOMATIC SWITCHING APPARATUS.

Patented Mar. 12, 1912.

APPLICATION FILED APR.1, 1910.

Hg. a.

W/fnesses: 92 //7ve/7/0/s:

rrnn s'raass mn'r enrich.

ALBERT M. BULLARJ), .DECEASED, BY MARION R. BULLABD, ADMINISTRATRIX, OF

WOODSTOCK, AND JOHN N. REYNOLDS, OF NEW YORK, N. Y., ASSIGNORS TO VVES'D- ERN ELECTRIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINOIS.

CONTROLLING SYSTEM FOR AUTOMATIC SWITCHING APPARATUS.

Specification of Letters Patent.

Patented Mar. 12, 1912.

Application filed April i, 1910. Serial No. 552,883.

To all whom it may concern:

Be it known that we, MARION R. BUL LARD,

. administratr ix, residing at Woodstock, in

the county of Ulster and State of New York, and J OHN 1N; REYNOLDS, residing at New York. in the county of New York and State of New .York, citizens of the United States,

are in possession ofan invention in a certain new and useful Improvement in Controlling Systems for Automatic Switching Apparatus, invented by ALBERT M. BULLA'RD,

deceased, and the said JOHN N. REYNOLDS, of which the following is a full, clear, concise, and exact descriptiom This invention relates to telephone ex change systemsof-the automatic or semi-automatic type in which the selection of lines or trunks for the extension of telephone transmission circuits is accomplished by mechanical selector switches, the object being to pro,-

vide an improved arrangement whereby the selective operation may be accurately and speedily accomplished. -T"""- One feature of the invention is concerned with the provision of simple, eflicient and economical means for selecting a desired line,

and for completing connections to such selected line, and comprises means whereby a plurality of selector switches may be. driven from a common source of power, the apphcationof power for driving any given switch being under the joint control of an electromagnetic mechanism individual to such selector, and an electro-magnetic mechanism common to a group of selectors, both ,of such mechanisms being controlled by a sender device over'a trunk or connecting circuit to which such'switch is connected.

In large automatic or semi-automatic systerns designed to accommodate many lines the number of selecting switches necessary toaccomplish selection rapidly increases as thenumber of lines increases, as may be readily understood, and it is, therefore, one

of the features of this invent-ion to reduce 'ithe'amount ofnecessaryapparatus by pro- 'viding a system involving controlling devices and a selecting or switching apparatus composed of a common or master driving mechanism with-which is associated a plurality of individual -selector switches, any

one of which may in t-urn'beoperated by the driving mechanism. In a system of this kind it is necessary to Provide means for a X sending device.

rapidly and accurately associating the master driving mechanism with any one of the associated individual selector switches durin the operation of setting up a connection.

- ore specifically this invention comprises as its main feature an automatic selector apother connection is utilizing the master mechanism, the association of the selector mechanism, with which is associated the trunk line last seized, with the master mechanismgwill be delayed until the cycle of operations ofthe master mechanism in connection with the selection in the first selector mechanism is completed. This cycle of operations is exceedingly brief in point of time and the call, even though delayed, will be retarded but little.

This invention also involves certain details of construction and organization of the circuits and apparatus by which all of the operations incidental to the proper establishment of connections may be accomplished.

For the purpose of clearly setting forth the invention, it is described and shown in connection with'mechanical selector switches operating in connection with what is known as the panel type of multiple and in connection with other specific mechanisms and arrangements of' circuits, but it must be understood that this invention is not limited to such switches, mechanisms or circuits further' than is specifically indicated in the claims appended hereto.

In the drawings: Figure 1 illustrates partly diagrammatically and partly in perspective the invention in connection with a master drivin mechanism, three individual selectors, a fin er system and a controlling or Fig. 2' is a side elevation partly in sections of the master driving mechanism, the two commutators and the stop magnet. Fig. 3 is a transverse vertical section of the master driving mechanism taken 1 on the line 3 of Fig. 2. Fig. i is aperspective view of the selector apparatus in- I cluding the master driving mechanism, two

commutators and the stop magnet, which are common to a plurality of individual selectors. There is also shown in this figure one of the individual mechanisms of this group of selectors. All of this apparatus is shown diagrammatically in Fig. 1. Fig." 5 is a horizontal section of the driving,

., holding and release mechanism individual another with strips of insulating material 'lector contact brushes can to each selector switch. Fig. 6 is asidel view of such individual driving, holding and release mechanism. Fig. 7 is av plan view of a sequence switch as used in connection with the master and individual mechanisms shown in Fig. 1. Figs. 8,9, 10 and 11 are detailed views of the brush carrier used in the selector shown in Fig. 1.

The scZe0t01".-The selecting mechanism in connection with which this invention is illustrated is shown partly diagrammatically and partly in perspective. in Fig. 1. It is of the master and individual type of mechanism arranged to be operated on what is known as the panel form of selector multiple. This multiple consists preferably of strips of metal having contact points spaced at regular lntervals along their entire length. These strips are placed one upon between, in such mannerv as to form vertical banks of contacts over which the sebe moved in a vertical direction, each vertical bank of contacts forming the cooperating terminals of a separate selector. The banks may comprise any desired number of sets of contacts and the selector'multiple may compriseas many multiple banks as may be conveniently used. As herein described, each bank is considered as accommodating contacts forming the transmission and test terminals of 100 lines, but it' should be understood that this invention is not limited to such construction.

In Fig. 1 a part of a bank of contacts as referred to above is indicated generally at- 84; The set of contacts 85, 86 and 87 form, respectively, the transmission and testterminals of the line 355, 357 and 356 to a further selector. The brush carrier 88 carries the brushes 89 and 90 arranged to contact respectively; with the terminals and 86, and the brushes 91 arranged to contact with the test terminal 87. This brushcarrier, which is shown'in detail in Figs. 8, 9, 10 and 11, and will be hereinafter more specifically 'described,is carried 'bya metallic tape 92, passing around the sheave 7 6 of the driving mechanism individual to the selector and an idle pulley (not shown) at the top of the bank of terminals. This tape when moved by the rotation 'with the terminals 85, 86

sheave 76 carriesjhe brushes into position to make contact with the terminals 85, 86 and 87 of the desired line, the selection being determined by the extent of the movement of the tape, the controlof which will be hereinafter fully set forth.

Briefly considered, plished by causing the brush carrier, which normally stands at the bottom of the first set of contact terminals to be moved over each set of contact terminals until the clesirecl set has been reached where the brushes are brought to. rest. i

As shownin, Figs. 8 to 11 the brushes '89, and 91 are supported on a carriage 88 slidably mounted upon a rod 9 1 which extends ,the entire height of the selector. This carriage 88 is securely attached to the metallic tape 92 by the screws 95, but is insulated therefrom by the insulating bushings 96. The carriage itself is composed of two body. portions 97 and 98 in order to render possible the accurate adjustment of the brushes with. relation to the terminals and to the tape 92. shown clearly in Fig. 11,; wherein the tape 92 is shown attached to the part 98 and the brushes are carried by the part 97 ,the two parts being securely fastened together by means of the bolt 99 while the cooperating serrations 100 upon the parts 97 and-98 serve to prevent their disadjustment after they have been once secured.

The brushes 89,90 and 91 are so arranged,

as will appear from Fig. 11, that they make mechanical contact with one terminal before leaving the preceding one, but owing to the inserts ofinsulation 101 upon their contact faces, do not make electrical'contact with more than one terminal at a time. These brushes moreover are arranged out of ali.ne ment with each other in order to bring them into proper relation with the set of terminals 85, 86., 87 which are arranged as will be seen from Figs. 8 and 11 in staggered relation, the lowermost being terminal 87 and the uppermost being terminal 85. This re; lation of the terminals is necessary owing to the construction indicated in Fig. 8, where it may be seen that such terminals are for ied by projections upon the conducting pieces 102 laid between sheets of insulation 103 as is usual in the construction of selectors of what is known as the panel type.

The brushes 89, 90 and 91 are pivotally l mounted upon the carriage 88 as will be seen and are pressed into contact and 87 by the springs 109. The brushes 91 are in electrical connection. through their mounting with the contact spring 104, which spring makes contact at all times with the rod 94 upon which the carriage moves, and thereby places the brushes 91 in constant electrical rea dily contact with this rod to which the selector selection is acconi- This construction is test lead is electrically connected. The brushes 89 and 90 are each mounted upon'a portion of the carriage insulated from each other and from the portion on which the brushes 91 are mounted and each in turn is electrically connected by means of the contact springs 105 and 106 with the auxiliary rods- 107 and 108'which also extendthe full height of the selector and serve to connect -and 90.

the transmission circuit to the brushes 89 Master dfiaiz'ng 'mckanism.'The' driving mechanism by which power issupplied for moving the brushes 89, 90 and 91' on the brush carrier 88 into contactual relation with the terminals 85', 86 and-87 is shown in Fig.

' '4 by the master clutch mechanism-13, common to a plurality of selectors, and the mechanism 14 individual to a single selector switching apparatus. The master clutch- 13, a side elevation of which, partly in section, is shown in Fig. 2, comprises a shaft 15 mounted 'upon' the uprights 16, extending 20L This gearwheel 20 is in permanent be,' and is preferably, that which. supplies power to the various apparatus of the exfrom the base 17, and has in/turn rotatably mounted thereon a sleeve 18, to one end of which is attached the disk 19 and to the other end of which is attached'the gearwheel mesh with another gearwheel- (not shown) upon a constantly rotating shaft, which may change. .Upon the shaft 15 is also mounted the sleeve 21 to one end'of'which is attached the 'gearwheel 22 and to the other end of which is attached the: disk 23. The disk 23, of soft iron or other magnetic material,

' forms the armature of the electromagn'et 25 into intimate frictional contact, causing the rotation of the disk 23. The arrangement of the disks 19 and 23 with respect to the pole piece 27 is such that when the disk 23 is attracted,-its periphery will be closely adjaits cent to the pole iece 27, in order thatit may be firmly held n contact with the disk 19, but will not be in actual contact with the pole piece itself. The gearwheel 22 meshes with the gearwheel 28 fixed upon the shaft 29, also mounted upon the uprights "16, Upon the shaft 29 arefalso mounted the commutators 33 and 34. Ihe commutator 33 cooperates withthe contacts 35, 36 and serves to make .and break the circuit between these contactsonce for every revolution of the metallic tape 92 to prevent the tape slip- 130 shaft 29.; The commutator 34 similarly 00- operates with the contacts 37, 38 to make and break the circuit between these contacts at each revolution of the shaft 29. The relation of the make and break of the circuits between contacts 35 and 36, 37 and 38, re-

spectively, will be hereinafter referred to, and set forth in the description of the operation of the system. 4

The disk 39 which is also mounted on the particular relation to the disk-39 by the springs 41, which are fastened at their re-t V aspective ends to the disk and the arm. This arm 40 cooperates with the armature 42 of the stop magnet 43 to stop therotation of the disk 39. when the magnet 43 has been de energized, but to permit a slight over-run by t springs 41, which overrun will, however, be

e disk 39 due to the extension of the shaft 29 has eotiperati-ng therewith the 40 mounted upon the shaft 29 and held in corrected and the disk 39 brought back into proper position by the contraction of the springs 41. p

Cooperating with a notch 44 upon the disk 39 is a pawlj45 mounted upon'the base 17 and so arranged that upon the reverse movement ofthe disk 39, due to the contrac-' tion of the s rings 41, the disk 39may not by any misc ance move too far in there- .verse direction. By means of the. arm 40 and the pawl 45 the disk 39 ,when stopped bythe armature 43 always'com'e to rest in precisely. the sameposition; The armature 42, which is normallyin a-netracted-.-position, due to the tension of) the "retracting spring 46, operates whenattracted-foripurposes hereinafter set forth to close the contacts 47 and 48, which are mounted upon an extension 49 from the base 17, insulated from each other and from the extension '49. 3

Upon the shaft 29 are fixed at properintervals as shown in Figs. 1, 2 and 4 the gearwheels 69 which transmit dividual driving mechanisms 14..'---1 Individual driving mechanism.-The inpower to the iny dividual driving mechanism shown in Figsfii 5 and 6 comprises the shaft- 70 to one end of? which is aflixed .the gearwhee1 71 which meshes with the gearwheel 69,- above .re-

ferred to, upon the main driving. shaft 29.

Adjacent to the gearwhe'el 71, and'also affixed to' the shaft 70 is the (115k 72 of soft iron, or. other magnetic material, which.

forms the armature of the electr'omagnet' 73, which when energized to move the shaft 70 so'thiit the clutch member 74 fixed on the other end of theattracts the disk 72 periphery thereof projecting pins-q ping upon the sheave. The shaft 70' is norinallyheld' in a position in which the clutch member 7 1 isout of cotiperativere lation with the clutch member 7 by means of the spring 78, as is plainly shown on Fig. ,5. The inner rim of the sheave 76 is made to form a ratchet by having cut therein the teeth 79. Cooperating .with these teeth '79 is the armature 80 of the electromagnet 81 by the energization of which the armature is adapted to be attracted out of cooperative relation with the teeth 79. The arma ture 80 is normally held retracted in en gagement with the teeth 79 by the spring 83. The movement of the sheave 76, therefore, depends upon the energization of the clutch magnet .73 and the rotation of the shaft 29. The shaft 29, however, having moved the sheave and tape into any given position, they may be prevented from returning by the armature 80 under .the control of the release magnet 81.

Sequence switch-To control the local circuits at the various parts of the system,

which local circuits must be established in definite order at successive stages of the operation, to bring into service different devices or parts as desired, there are used automatic switching appliances whichare termed sequence switches. There is, for

example, a sequence switch associated with the master driving mechanism and a se quence switch "associated with each individual driving mechanism as is indicated: upon Fig. 1 ,of the drawings; These se- "each consist of amovable switch operating member, a number of cir-' cuit-changes being made in sequence as said member is moved from one position to an other; an electromagnet and a constantly rotating source of power, the connection of, which with the movable member is con-' trolled by saidmagnet for advancing said movable member. In each position to which -the movable member of the sequence switch is advanced a set of circuits. is established by whicha given operation 'of the device under control is made possible and at the same time another circuit is prepared for energizing the controlling magnet of the sequence switch. This new energizing circuit for the controlling magnet; -.W1ll be (Fig. 7) 173 is a gear" with the various portions of'the ap closed at the proper timeto advance the se-' quence switch to the nelxt position in which itewill'establish a new setof circuits; and bring about a-new operation or electrical condition of the device or devices under'its" control and so on. One form of, sequence switch mechanism is shown in Rig.- 7"and1s also diagrammatically shown iii-connection" aratus,

' in Fig. 1 as for instance the indivi ual-sequence switch 300 andfthe master sequenceswitch 400. In this formof sequence switch heel driven by a and out o 'rious contact springs 187 and 189 as the cm constantly rotating shaft, not shown. This gearwheel 173 is fixed upon ashaft 171 mounted upon a base 172 and having at the end opposite the gearwheel 173, a disk 174 of brass, or other non-magnetic material. Adjacent to the disk 174 is a disk 176 fixed on the shaft 177 and forming the armature of the clutch magnet 178. This disk 176 is formed 0 soft iron or other magnetic material and has on the face thereof adjacent to the disk 174: a friction sic-face of suitable material 1179 coiiperating aith a similar friction surface upon the disk 174; Upon the energiv ation of the electromagnet 178'the disk 176 will be drawn ad jacent to the circular pole piece 180 of th( electromagnet, and will be brought into intimatefrictional contact with the disk 174 which is constantly rotating and .the tw disks will, therefore, rotate together. Upoi the shaft 177 is also fixeda gearwheel 181 which meshes with the gearwheel182 fixet won a shaft 184. which is mounted on a has 183. On this shaft- 184:31'8 fixed the car wheels 185 made of insulation, upon th outer rim of which are formed the cam sui faces 186 which cooperate: with the cor tact springs-188w force such" springs int contactual relation with the v:

wheels 185 revolve, the movement of tl springs 188 depending upon the formatu and position of the cam surfaces 186 up( the cam wheels.

A special switch is preferably provided control a'local' circuitithrough the electr magnet 17 8, whereby when the initial ene gizing circuit is broken by one of t switches the motor magnet may still be e citedby current in the local circuit until t next intended stopping place of the rota element is fully reached. As shown in F 7:a cam 200 for operating a local cont:

' 201 is adapted to be engaged by a sp'ri 202, said cairi beingprovided on its mar; with a plurality "of teeth and saidspri 202 being provided on its free end with ofi'set portion. When the oifsetportion gages a-highjpart of the cam'200'the spr 202 closes a local contact 201 which fconti .the local circuit for the motor magnet. teeth of the cam 200 have inclined edges that theofiset portion of thespring 202 a:

riding over the point of the tooth is foi downjthe opposite slope by the spring p sure and thus tendsto push against the tofcOntinuethe rotation thereof until offset portion reaches'thebottoni of the lowing notch and the contact-201 is pletely'bpened. The rotary element is broughtto'rest accurately in each of the sitions in'which it is intended to stop. the operation of the device each circuit 'firstbe closed for the clutch magnet thn one of the springs 188 and one or the the sequence switch of the contact springs 187 or 189; Then as. the motor magnetis excited and the shaft of begins to rotate the contact through which the clutch magnet was initiallyexcited may be broken, butthe local circuit will be maintained for the mo tor magnet through the contact 201 and the rotary element will thus continue; to ad.- vance until the contact 201 is opened.' As these special contacts are closed only while the rotary element of the sequence switch is in transit from one position to the next, thenumbers are placed on the side of thes'witch lever opposite from the contact and indicate positions in which said contact is open. j F astened upon one end of the shaft 184 is a stopw-heel 190 formed with notches upon its periphery in which the projection 191 upon the armature 192 of the electromagnet:

193 adapted to rest when" said armature is retracted to stop the rotation of the shaft promptly and accurately when the posit-ion desired has been reached and the electromagnet 193 has been deenergized. The spr1ng194: serves to retract thearmature 192 upon the deener'gization of the'electromagnet 1 93. F cinder iiism by means of which the individual sediagrammatically contact members arranged lectors are picked up one ciated with the master mechanism is shown diagrammatically iii Fig. 1 and comprises generally a clutch magnet adapted to engage a rotatable magnetic disk carrying an I arm upon which are mounted two electrically separated brushes adapted to engage 1n I'OWS -c0ncentric to said rotatable disk. The said disk is provided on its margin with teeth or notches adapted to be engaged by the free end of a swinging lever which lever is adapted to be drawn intoengagement with the teeth on the disk by-the action of a holding maginet'located between the ends of said lever. There are the same number of teeth or. notches in the margin of the magnetic disk as there are pairs of brush contacts and the operation of the holding or looking magnet serves to bring the disk to rest with the brushesthereon resting upon a pair of con tacts( The pivotal end of the swinging -lever is "adapted to control local contact springs for opening an closing circuits t "rough various parts of the apparatus.

Operation-Iii Fig. 1 there is shown an embodiment of the invention including three individual selectors 351, 35.2 and 353, a master driving mechanism 13 and a finder m 'hanism 4:74a- The selectors in the system shown are controlled,-

by means of sending mechanism operating upon what' is lmown as revertive lm-puise control. Brieflystated this control is accordringtothe following plan: When connection is made with the selector a controhng or movement of the selector.

'mecham' smr-The finder mecha by one and assoa understood, however,

Associated with the circuit 303,,

stepping circuit is established, includinga' line relay-or magnet at the master driving mechanism and a ralay or magnet at the sender adapted to operatea step by'step mechanism. The line relay at the master driving mechanism closes a local circuit thr clutch magnet which starts'the maste driv- I ing mechanism in rotation; in such-rotation an interrupter is operated by the master,

driving mechanism to intermittently short circuit the-line, causing pulsations in the controlling circuit in unison with the advance of the selector, which pulsations cause the stepping. relay ormagnet at the sender to operate the step by step mechanism thereof and measure oii at the sender the extent of When the sender apparatus reaches a predetermined ipoint which the operator has selected it completes a circuitfor a'istop relay which renders inoperative the line relay at the master driving mechanism t-h'us bringing that particular selecting operation to an end. So much of the sender apparatus 361 is also shown, as is necessary for a complete understanding of the invention, 1 form a part of this invention, itis only partially andrdiagranunatically, sh Contacts438, 439, 440 and 4A3 indica e-common connecting: points between the circuits of the severalindividual selectors and the master. T-he trunk conductors 303, 304, which may form a part of the telephone transmission circuit lead to a selecting mechanism 352 by which such telephone transmission circuit may be extended to the, conductors 357, 355' or other similar conductors. A simie lar trunk circuit leading to the selecting mechanism 353 is indicated 2135362; The selector associated.with the conductors 303, 304:, is onein which it is desired to select a certain line of a group of lines. It should that the invention is not limited to selectors of this character but may be used with. equal advantage in connection with selectors in which connection is to be made with an idle trunk line of a group, any one of which will'equally well serve the purpose of the connection. 304, by any suitable means are the leads 369and 371 of the sender apparatus. The connection of these sender'leads to the circuit 303, 304 may be either permanent or temporary, as may bepreferred, but since this-connection forms no part of this invention it is only diagrammatically indicated as at 310 and 311.

The operation of the various parts of the system through which the connection of a desired line with the selector 352 is accom-- plished isas follows':- 'Ehe sender apparatus is first ope 'ated to energize a, stop relay 303 to place a shunt around the high resistance 2105. Prior to the energizat )n of the stop relay 306 a circuit existed from the'battery ugha but/since theisender does not quence switch contact 370, winding sistance,'is insufiicient to energize either the 2 however, and by means of its front contact 326 and back to battery.

308, stepping relay 307, high resistance 305, conductor 367, conductor 369, contact ter-- min'al 311, conductor 304, individual se- 313 of line relay 314, conductor 312, conductor 303, contact terminal 310,"conductor 371, conductor 366 to ground, 309. The current in this circuit, however, due to the inclusion of the high resistance'305 and the fact that winding 313 of line relay 314 is also of high res'tepping relay 307 or the line relay -314. However, upon the pulling up of the armature of stop relay 306, the shunt is, closed around .the high resistance 305 and suflicient current thereupon passes through the circuit traced to energize the line 1 relay 314, although not suflicient to energize the step ping relay 307 because the high resistance winding 3130f line relay 314 is stillrincluded in thecireuit. The completion of this circuit causes the line relay 314 to operate,

to drive the individual sequence switch 300 front-its rest or zero POSItlOII to position 1 by.- means of the following circuit: battery 350,- the armature andfront contact-331 of the relay314, conductor 320, sequence switch contact 319,'conductor 322, clutch magnet 301, and stop magnet 302 of the individual sequence switch 300 and ground back to .The special individual sequenceswitch contact 323 serves to insure the movement fully into its first position, being closed at all times except when the sequence switch is in the positions noted adjacent this contact.

At position 1 sequence switch contacts 319 and 370 are opened and contacts 318, 324, 325 and 373 are closed. The closure of sequence switch contact 31 8 makes-provision for. the restoration of the individual sequence switch at any time by the release of the line relay 314.- Theindividual selector mechanism is now in readiness to be picked up by the-finder, and the closure of sequence switch contact 325, provided the master mechanism is at rest, allows current to flow. from battery 416, conductor 422, master sequence switch contact 415, conductor 417, finder relay 418, conductor 405;- conductor 327, sequence switch contact 325 to ground This causes the operation of finder relay 418, which by its armature and front contact causes the energization of the finder clutch 475 by means of thefollowing circuit: battery 416, armatureand front contact 453- of relay 418,

' conductor 419, finder contact 411, conductor 454, clutch 475 to ground and back to bat- .ltery. At position 1 individual sequence sponds to this particular individual selector 47 5 causes the finder to revolvein its hunt for the terminals. of the-individual selector 352, with which the sender mechanism is associated over the -trunk leads 303, 304.

324 to ground 326 and back to battery. Tlns causes the operation of-the finder stop mag net 409 bringing the detent 437 into engagement with the corresponding ,tooth on the come to rest with the brushes 451 and 452 making contact with the terminals 406 and 407. At the same time the operation of the armature 456 opens the contacts 411 to remove the power from the driving clutch 47 5.

The. operation of the ar mature 456 at the same time closes the contacts 412 'to cause the individual sequence switch to move into the second or selecting position'by means of ratchet wheel 455, thus causing the finder to I the following circuit: battery 416, armature and front contact 453 of relay 418, conductor 419, contacts 412, conductor 457, contact brush 451, contacttermina-l 406, conductor 403, conductor 330, sequence switch cont'act succeeding positions the circuit from -the battery416 through the finder relay 418 is opened and remains open until the operationof the particular selector with which this individual sequenceswitch is associated is completed'and that sequence switch has been returned to its normal or zero position. This arrangement makes it impossible to operate the finder throughthe operation ot-a succeeding selector until the one which has last become associated with the master driving mechanism has completed its operation and the individual sequence switch associated with that selector has returned to its zero or normal position' Thus since there i: but one individual selector per pair of con tacts on thefihder there can be only one 0: such selectors associated with the maste:

driving mechamsm at one time,

Inposition 2 of the individual sequenc switch the sequence switch contact 348 close to operate the release magnet 81 from bat tery 375, sequence switch contact 348, C01 ductor 376, releasemagnet 81 to ground 34 and back to battery, and the sequence swit contact 343 closes to operate the individu clutch 73 from battery 342, sequence-swih contact 343, conductor 345, clutch lnagn 73 to ground 377' and back to battery. 1 long, therefore, as sequence switch contzu mechanism 352. The energization of clutch 848 and 343 remain closed the sheave T6 373, conductor 374, clutch magnet 301, and

' switch contacts 317,333 and 335 closing to contact 335, conduct-or332, conductor 433,

'brushe's 35 and 36 on commutator 33-, coni for selection.

to cause the individual driving mechanism will be coupled through the individual clutch to the master driving shaft 29 and the release magnet will remain operated holding the pawl 80 out of engagement with the teeth 79 on the sheave 76. Also while the individual sequence switch is' in position 2 the master driving mechanism is in readiness for opera-- tion with the individual selector under CQDr trol of the sending mechanism 361, sequence complete the selecting circuit by connecting the selecting relay 426 in a shunt around the high resistance winding 313 of the-lingrelay314: conductor 354, sequence switc ductor 447 winding 425 of relay 426, conductor 458, conductor 331,-sequence switch contact 333, winding 315 of line .relay 314, sequence "switch contact 317 toconductor 371. The winding '425 of selecting relay 426 and the winding-315 of theline relay 314 both being of low resistance this circuit just traced acts as a sufficient shunt around the high resistance winding 313 ofrelay 314 the operation of the stepping relay.307.'

When theselecting-relay is energized it serves, by means of its front contact, to advance lhe niaster sequence switch 400 from its zc'ro or restingposition to position, 1 This circuit may be traced from battery 424, armature and front contact 430 of relay 426, conductor 463, sequence switch contact 431, conductor 450, clutch magnet 401, and stop magnet 402 of master sequence switch 400 toground and back to battery. At position 1 of the master sequeliceuswitch the sequence switch contact 43l'opens to stop the movement of the; switch, and contact 432 closes to cause the.

operation of the master mechanism through .the following circuit: battery 424, armature and front contact 430 of selecting relay 426,

sequence-switch contact 43 con ductor 434, stop magnet 43 to ground 459 and back to battery. This energizes the stop magnet 43 withdrawing the armature 42 from engagement with the arm 40 on the stop wheel 39.

The attraction of the armature 42 also closes the contact springs 47 and 48 and coinpletes a circuit which may be'traced from battery 445, main driving clutch magnet 25, conductor 444; contacts 47 and, 48 to ground 459 and backto battery. I The closure of this circuit through the master clutch magnet 25 couples the shaft 29 through the gearing shown, to the constantly rotating shaft 15. The shaft 29 and the sheave 76 of the indi- .vidual selector will now move together owing to the energiz'ation of the individual clutch magnet 73. This will cause the mesistance -winding 313 of the line relay 314-is 7o openedby the contacts 35 and 36 resting upon the insulated portion of the commutator' 33. The rotation of the commutator 34, also attached to shaft 29 hasfhowever,

closed a circuit to maintain the selecting re- 5' lay 426 energized while the above shunt cir- .cuit is open by the closure of the circuit from the battery 436, contacts, 37;;and -38,

relay 426 to ground and'back-to battery.

The openingof the shunt circuit around the high resistance winding 313 of line relay 314 at thecontacts 35 and 36 has'so reduced the current in the circuit as to cause 5 the deenergization of the stepping relay however, circuit is again made through the metallic portion of the commutator 33 to close the shunt circuit around the high resistance 313 of line relay 314, and upon'a slightly further rotation of the shaft 29 the local energizing circuit ofthe selecting relay 426 through the winding 427 thereof is opened by the contacts 37 and '38 coming upon the insulated portion of the commutator 34. If at this stage of the operation the high resistance'305 in the senderremains shunted by'the armature of the cutofi relay brushes caused to move upward over the sets of contact terminals until the energization .an'd denergization of 'the'stepping magnet 307 has stepped the sender device to normal, at which time the stop relay'fwill ,be-.

comedeener ized and openithe shunt around the high resistance 305. When now the ratat'ion'of the shaft 29 has-caused. the opening of the local energizing circuit through the winding 4 27 of the selecting relay 426* and has again closed the shunt circuit around the high resistance winding 313 of line relay 314, insufficient current will pass through the winding 425 of the selecting relay 426, due to the presence in the circuit of the high resistance 305, to maintain said selooting relay 426 energized and its armature will be retractedopening the circuit through thestep magnet 43 and closing a circuit' from battery 424, armature and back con- 307. As the shaft 29 continues to rota e,\\

' 306, the rotation of the shaft29 and the 100 tact 4290f the selecting relay 426, sequence 1 switch contact 428, conductor 450, clutch magnet 401 and stop magnet 402 of the master sequence switch 400 to ground and back to battery. This will cause the master se-' quence switch 400 to move from its first to and the metallic portion gf 'theizommutatorw 34, conductor 446, winding 427 of selecting Q its second positionfat which point the seswitch 300. This 'causes'the movement of quence switch contact 421 will be momenthe individual sequence switch fromits tarily closed to drive the individual sethird to zero or normal position. At this quence switch from itssecond or selecting position sequence switch contact 340 is closed 5 position toits third or talkingosition over completing a circuit from battery 341, con a circuitwhich may be traced rom battery, ductor 349, ofi? normal contact 344, conduc- 460, sequence switch contact 421, conductor tor 346, holding magnet 81 of the individual 4.61, conductor 329, sequence switch contact selector to ground'347. This energizes the 37 2, conductorv 374, clutch magnet 301and" latter and causes the holding pawl 80- to be 0 stop magnet 302 of the individual sequence withdrawn from engagement with ratchet switch 300 to grou'nd. and back to battery. teeth 79 on the sheave 76. This allows the Upon leaving position 2' contact 348 is r'b'rush carrier 88 to be returned by gravity opened to denergize the release magnet-81' to its normal position at the bottom of the to. permit its spring toretract its armature bank of terminals, where the OE normal con- 15 into engagement with 4 the corresponding tact 344 is opened allowing the'holding magtooth 7 9 on thesheav'e 76 to maintain the 'net 81 'to be released.

brushes elevated- In moving into this new We claimposition the individual sequence switch re- 1. In a telephone exchange system, the leases the individual selector from conneccombination with a plurality of individual tion with the master mechanism and its as-'- selectors','of a master driving mechanism for sociated aparatusbyopening sequence switch said selectors with which only one of said contacts 317, 324, 325, 333, 335, 343, 348 and selectors can be associated at a time, and 372. At the same time the master-[sequence means operating toassociate said selectors switch 400 continues on from its second poseverally with said master mechanismsition to its normal or zero position where 2. In a telephone exchange system, the it isv stopped by the opening of sequence combination'with a plurality of individual switch contact 428. This leaves the master selectors, of a master mechanism adapted mechanism in position to. be picked up by to drive said selectors and means operating any other of the associated individualseto" associate said individual selectors sev- 3g lectors on which acall may appear, as 'seerally'with said master mechanism and to quenceswitch contact 415 is again closed prevent the simultaneous associating of a allowing finder relay 418 to be energized by plurality of said selectors therewith.

ground from any individual sequence 3. In a telephone exchange system, the switch. combination with a plurality of individual At position 3 of the individual sequence selectors, of a master mechanism adapted switch the following contacts are closed to tqdrive said, selectors, a finder device an hold theconnec'tion andzcompl'ete the talkranged to associate saidqngter meohanisn ing circuit: 316, 334, 336 and 337. Assum-- with any one 'of said selectors, andswitching ing now-that the brush carrier. has been apparatus associatedwith each of said se 4 brought to rest with the contact brushes 89, lectors to control said finder device.

90 and 91 resting upon the contact termi- 4. In a telephone exchange system, th nals 85, 86 and 87, of the desired line, it will combination with a plurality of individua be seen that a-eircuit is completed from the selectors, of a master meohanism adapted t battery 360. located at the distant end of the drive said selectors, a sequence switch assc as selected line through the resistance 359, conciated with each of said selectors, and

tact 358, conductor. 356, contact terminal 87, finder device arranged to associate sai brushes 91, conductor 339, sequenceswitch master'mechanism with anyone of said 51 contact 334, winding 315 of line relay 314,- lectors throughcontacts of its associateds sequence switch contact 316 to ground. The quence switch.

50, closure of this circuit serves'to maintain the 5. In a telephone eitchange' system, tl

- line relay 314 in its operated position, and combination with a plurality of .individu also acts as a shunt on the..battery 360 and selectors, of a master mechanism adapted the resistance 359 to maintain the selected drive said selectors, a sequence switch inc line in the busy condition. vidual to each of said selectors, and a find 55 \Vhen it is desired to restore the individual device arranged to associate said mast selector to its normal position the contact mechanism with any oneof said selecto 358 at the distant selector is opened by any said finder device being initially control] suitable means, causing the desmgnanon by one of said sequence switches and the:

of the line relay 314, which in turn drives after controlling said sequence switch. so the individual sequence switch to its normal 6. In a telephone exchange. system, i positionthrough a circuit which ma be combination witha plurality of individi traced from battery 350, contact 330 0 line selectors, of a master mechanism adap relay 314, conductor 321, sequence switch to drive said selectors, a finder device contact 318, conductor 322 clutch 301 and ran ed to a'ssociatefsaidmaster mechani -65 stop magnet 302. of the individual sequence wit any one of said selectors, and me combination with a plurality of individual selectors, of a master mechanism adapted to .drive said selectors, a sequence switch 1n .dividual to each of said selectors, a finder device arranged to associate said master mechanism with'any one of said selectors,

said finder being initially controlled by one of. said sequence switches and thereafter controlling said sequence switch, and a master sequence switch under the joint con trolof said finder and one of said sequence switches arranged to control said master mechanism.

8. In a telephone exchange system, the

combination with a plurality of individual selectors and individual sequence switches therefor, ot a master mechanism adapted to drive said individual selectors, a finder.

arranged to associate said selectors severally with said master mechanism, said finder embracing movable brushes and a plurality of terminals connected with the several selectors, means controlled by the operation of said sequence switches to cause the movement of said finder brushes and means for bringing said finder brushes to rest upon the contact of a selector the associated sequence switch of which has been operated.

9. In a telephone exchange system, the combination with a plurality of individual selectors and individual sequence switches therefor, of a master. mechanism adapted to drive said individual selectors, a finder device arran ed to associate said selectors severally with said master mechanism, said finder device embracing movable brushes and a plurality of terminals connected with the several selectors, a clutch magnet con trolled by the operation of one of said sequence switches to cause the movement of said brushes, said sequence switch in its operation also grounding a contact on the 1 finder terminal corresponding with the selector with which thatsequen'ce switch is combination with connectin associated, and a holding magnet for said brushes operated when the cooperating brush engages said groundedtcontact.

10. In a telephone exchange system, thecircults and a plurality of individual se ectors adapted to extend said connecting circuits, of a master mechanism adapted to drivesaid' selectors, a finder device arranged to associate said-selectors severally with said master mechanism and means operating upon the completion of selection to free the operated selector from said master driving mechanism and render said master mechanism and finder free to become associated with the selector through which the succeeding connection is to be extended.

11. In a telephone exchange system, the combination with connecting circuits and individual selectors adapted to extend said circuits, of a' master mechanism adapted'to drive said selectors, a finder device arranged to associate said selectors severally with said master mechanism and switching apparatus cont-rolled by said finder device to operate said mechanism and upon the com pletion of selection to disengage said master mechanism and finder ,from the -operated selector and render them free to be associated with the selector over which the succeeding connection is to beextended.

In witness whereof, we hereunto subscribe our names this 30th dayof March, 8 A. 1)., 1910, and 31st day of March, A. 1)., 1910, respectively. "1 MARION R. BULLARD, Advrt-im'stmtria: of the estate of Albert M.

Bullarz, deceased.

- JOHN N. REYNOLDS.

Witnesses as to signature of Marion R. Bullard: i

R. M. Roo'rr, HARRY T. CRISP.

Witnesses as to signature of John N. Reynolds: MORGAN WASHBURN, Jr., Invmo MAoDoNALo.

Copies of this patent may be obtained for five cents each, by addressing th Commissioner of Patents, Washington, D. O. 

